[infinispan-dev] simulating connection timeout

[Manik Surtani]

What is this for?  Perhaps just mock up the client to use a mock socket?

On 19 Jan 2012, at 12:57, Bela Ban wrote:

> If this is done in Java code, you could use byteman to change the behavior.
> 
> Intercepting and changing the data flow in the TCP/IP stack itself gets 
> more tricky; you have to insert a packet filter and then drop/reorder 
> packets. In Java, you might be able to use jnetpcap, which allows you to 
> get access to the individual packets.
> 
> Maybe iptables will also allow you to do this, but it's rather static.
> 
> On 1/18/12 10:05 PM, Michal Linhard wrote:
>> Hi all,
>> 
>> probably stupid question from the area of java server programming and
>> networking if anyone's interrested:
>> (otherwise sorry for spam)
>> 
>> is there a simple way of creating a server in java that would always
>> give me connection timeout ? (not connection refused, nor socket timeout
>> during read)
>> is it even possible to control establishing tcp connection from java ?
>> 
>> what layer does control this ?
>> it seems that once you bind a socket the connections are automatically
>> established.
>> probably on some JVM level ?
>> so when I get
>> 
>> java.net.ConnectException: Connection timed out
>> 	at sun.nio.ch.SocketChannelImpl.checkConnect(Native Method)
>> 	at sun.nio.ch.SocketChannelImpl.finishConnect(SocketChannelImpl.java:567)
>> 	at sun.nio.ch.SocketAdaptor.connect(SocketAdaptor.java:100)
>> 	at org.infinispan.client.hotrod.impl.transport.tcp.TcpTransport.<init>(TcpTransport.java:80)
>> 
>> 
>> this means that server JVM or OS networking layer or whatever was so
>> stressed that it didn't have time to respond with SYN,ACK flagged packet
>> to establish the connection ?
>> 
>> m.
>> 
>> 
>> ----------- my test code:
>> public class EchoServer {
>>     public static void main(String[] args) {
>>        try {
>>           ServerSocketChannel serverChannel = ServerSocketChannel.open();
>>           InetSocketAddress isa = new InetSocketAddress("localhost", 9090);
>>           serverChannel.socket().bind(isa);
>>           Thread.sleep(20000);
>>        } catch (Exception e) {
>>           e.printStackTrace();
>>        }
>> 
>>     }
>> }
>> 
>> public class EchoClient {
>>     public static void main(String[] args) {
>>        long startTime = System.currentTimeMillis();
>>        try {
>>           SocketAddress serverAddress = new
>> InetSocketAddress("localhost", 9090);
>>           SocketChannel socketChannel = SocketChannel.open();
>>           Socket socket = socketChannel.socket();
>>           socket.connect(serverAddress, 5000);
>>           socket.setSoTimeout(5000);
>>           BufferedInputStream socketInputStream = new
>> BufferedInputStream(socket.getInputStream(), socket.getReceiveBufferSize());
>>           BufferedOutputStream socketOutputStream = new
>> BufferedOutputStream(socket.getOutputStream(), socket.getSendBufferSize());
>>           PrintWriter out = new PrintWriter(socketOutputStream);
>>           out.println("Hello");
>>           out.flush();
>>           BufferedReader in = new BufferedReader(new
>> InputStreamReader(socketInputStream));
>>           System.out.println(in.readLine());
>>        } catch (Exception e) {
>>           System.out.println("Exception occured after " +
>> (System.currentTimeMillis() - startTime) + " ms");
>>           e.printStackTrace();
>>        }
>>     }
>> }
>> 
> 
> -- 
> Bela Ban
> Lead JGroups (http://www.jgroups.org)
> JBoss / Red Hat
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--
Manik Surtani
manik at jboss.org
twitter.com/maniksurtani

Lead, Infinispan
http://www.infinispan.org